Mineral oil compositions



Patented Oct. 18, 1949 .IMINERAL OIL COMPOSITIONS Frank J. Glavls, Elkins Park, and Harry T. Neher,

Bristol, Pa., assiznors to Riihm & Haas Company, lfliiladelphia, Pa.. a corporation oi Delaware No Drawing. Application January 21, 1947, Serial No. 723,462

8 Claims (Cl. 252-334) This invention deals with compositions of matter comprising a major proportion of a mineral oil and minor proportions of an oil-soluble petroleum sulfonate and a water-insoluble, oilmiscible araliphatic polyether alcohol of the formula wherein R is an alkyl group of four to twelve carbon atoms. These compositions are useful as slushing oils, lubricating oils, and the like.

It has already been proposed to add petroleum sulfonates to mineral oils to impart to the resulting compositions anti-corrosive properties or de.- tergent action. Actual, practical results have varied greatly. In many instances, the protective value of the compositions has been insufflcient at moderate concentrations of petroleum sulfonate. While larger proportions of such sulfonate have then been tried, the resulting compositions have not been proportionately more efiective and disadvantageous properties have been thus developed. While compositions have been devised which give sufilcient protection for slight or moderate exposure to corrosive conditions, these often fail when conditions become slightly more severe. This is particularly true in thin film applications. Furthermore, there has been considerable variation in results from a given formulation. Often it is desirable or even necessary that the composition not only protect metals from corrosion but also provide safe and eflioient lubrication. Few compositions of the art have had this desirable combination of properties. It is readily attained, however, by practicing this invention which, at the same time, corrects many of the shortcomings and deficiencies of compositions of the prior art.

It is an object of this invention to provide compositions of improved anti-corrosive action. It is an object to provide compositions which supply a' high degree of protection of metal surfaces, I

by the addition of oil-soluble petroleum sulfonates and an alkylphenoxyethoxyethoxyethanol. The compositions of this invention provide excellent protection of metals against moisture and many aqueous solutions, whether used in thick or in thin film applications, and at the same time may serve as lubricants for the surfaces of the metal.

An essential component of the compositions of this invention is an oil-soluble petroleum sulfonate. This may be an alkali or alkaline earth salt, including the lithium, sodium, potassium, calcium, strontium, and barium salts of the hydrocarbon sulfonates prepared by the treatment of petroleum oils with sulfuric acid followed, for example, by treatment with a base of the metal. While the alkali or alkaline earth sulfonates are those most commonly used and most readily available, petroleum sulfonates of other metals may .be used if they are soluble in the particular mineral oil selected to an extent of 1% to 10%. The most efiective sulfonates are those of moderately high molecular weight. These are usually regarded as having molecular weights of about five hundred to about seven hundred. Yet any of the oil-soluble petroleum sulfonates may be used which have molecular weights from about four hundred to about one thousand, the range of five hundred to seven hundred being preferred. The oil-soluble metal sulfonates may be used in amounts from 0.5% to 7.5%, with concentrations of 1% to 5% being most desirable for a balance of efllciency and economy. While more than 7.5% may be used in conjunction with an alkylphenoxyethoxyethoxyethanol in a petroleum oil, there is usually no practical advantage gained thereby except for the preparation of concentrates which are diluted before use. Since it is generally considered desirable to use as small amounts of additives as will produce desired results with some factor of safety, the amount of petroleumsulfonate actually used should depend on the intended application and the conditions there to be met.

The sulfonate may be used at a concentration I which, if it were the sole additive, would not provide an acceptable degree of protection to metals. Upon addition of an alkylphenoxyethoxyethoxyethanol in small amount, however, the resulting composition gains greatly in effectiveness. Yet this latter compound as a. sole additive mayactually promote corrosion. It is desirably used more or less in proportion to the amount of sulfonate taken. The practical limits are from 0.05% up to 3% of an alkylphenoxyethoxyethoxyethanol which is preferably used in an amount no greater than the amount oi petroleum sulfonate being used.

The polyether alcohols which are used fall within the formula @ocmomocmcmoomcmon where R is an alkyl group of four to twelve carbon atoms. Thus, R may be butyl, amyl, hexyl, heptyl, octyl. nonyl, decyl, undecyl, or dodecyl in straight or branched chain arrangement with the group 'being normal iso, secondary, or tertiary and with the alkyl group in ortho-meta, or para positions. When this group is tertiary, particularly interesting compounds are at hand from the point of view of economy and effectiveness. The phenyl nucleus may contain more than one hydrocarbon constituent, as in the case of the nucleus from alkylated cresols or xylenols or alkylated ethylphenol or other alkylyated hydrocarbon-substituted phenols, as in the case of groups derived from poly-hydrocar-bon-substituted phenols such as tert.-butylphenylphenol or butyl cyclohexylphenol. The essential requirement of the alkylated phenyl group is that it impart ready oilsolubility and be free from polar or reactive groups.

As is known, compounds of the above formula are prepared from alkylated phenols by reaction with three moles of ethylene oxide or by reaction with a triethylene halohydrin in the presence of a base.

In addition to an oil-soluble petroleum sulfonate and the oil-soluble ether alcohols above defined, there may be used in the compositions of this invention one or more additives providing special properties, such as antioxidants, oiliness agents, pour point depressants, viscosity index improvers, extreme pressure agents, thickening agents, including petrolatum and waxes, and the like.

The beneficial effects of the combination of sulfonate and the above-defined ether alcohols have been established with oils' from parafllnic, naphthenic, and asphaltic stocks, and combinations thereof. Furthermore, oils have been used which were refined by distillation, by extraction, and by a combination of distillation and extraction. Oils have been studied varying in viscosity from about one hundred seconds to fifteen hundred seconds Saybolt at 100 F. and varying in viscosity index from zero to well over one hundred. In every case, the addition of an alkylphenoxyethoxyethoxyethanol has markedly improved the properties of a petroleum sulfonate inoil.

The following examples show typical results obtained with compositions of this invention:

Example 1 A series of alkylphenyl ether alcohols was prepared having one, three, fiive, eight, and thirteen ether groups, the alkyl group being octyl. There was also prepared a 5% solution of a sodium petroleum sulfonate of a molecular weight of about 450 in an S. A. E. lubricating oil prepared by solvent extraction of a fraction from mid-continent crude. This oil had a viscosity index of 115. Solutions were made with one per cent of each of these ether alcohols in the 5% soulfonate solution. These solutions were then tested on standard steel panels which were hung in a cabinet 4 at 120 F. maintained at relative humidity. Panels coated with the 5% sulfonate solution without an ether alcohol were rusted within twenty-nine hours. The panels coated with the solution containing sulfonate and the compound having thirteen ether groups were rusted within seventeen hours. The panels with the sulfonate and ether alcohols of eight and flve ether groups, respectively, were rusted within two days time. Panels with the sulfonate and alcohol with a single ether group rusted within about three days. The panels with the sulfonate and the compound with three ether groups were intact at the end of ten days, when the tests were discontinued.

Example 2 In an oil prepared from mid-continent stock, having a viscosity index of 116 as a result of solvent extraction and having a viscosity of 530 seconds Saybolt at 100 F., there were dissolved 0.1% of a thiophosphate as an antioxidant and 1.5% of a calcium petroleum sulfonate of relatively low molecular weight. Panels coated with this mixture were rusted in the humidity cabinet at 120 F. within three hours after initial exposure. To a portion of this solution there was added one per cent of tert.-butylphenoxyethoxyethoxyethanol; and this mixture was applied to steel panels, which were'exposed to a saturated atmosphere at 120 F. No rust appeared until after sixty-eight hours. This composition was found to be a good, stable. anti-corrosive engine oil with detergent properties.

Example 3 time the tests were discontinued. During the same period, tests were run with solutions of the same sulfonate with the same oil, to which was added only 0.25% of the same ether alcohol in one case and 0.5% in another case. Both of these compositions efiectively prevented rusting for over 168 hours.

Example 4 A series of solutions was made in which a highgrade petroleum sulfonate of a molecular weight about five hundred, regarded in the trade as a very efiective rust-preventive agent, was dissolved in a mid-continent S. A. E. 30 motor oil to give solutions containing from 2% to 10% of the sulfonate. Steel panels coated with this series of sulfonate solutions all rusted in seventy to eighty hours when placed in the humidity cabinet referred to in Example 1. Addition of 0.1% of tert.-octylphenoxyethoxyethoxyethanol to the 2% solution increased the protective period to over ninety hours, while addition of 0.1% to the 7% solution increased this period to over 150 hours. Addition of 0.2% of this compound to the 5% sulfonate solution gave protection for over hours. Additions of 0.5% or 1% to the 5% sulfonate solution gave full protection for over 168 hours. This oil without any sulfonate or ether alcohol permitted rusting within two hours under the conditions of test described above.

A 2 solution of strontium petroleum sulfonate' of a molecular weight between five hundred and six hundred was made in an oil useful for lubricating aircraft engines, an S. A. E. 60 Pennsylvania oil of 100' V. I. containing an antioxidant, and to difierent portions thereof was added 0.5% and 1.0%, respectively, of diisobutylphenoxyethoxyethoxyethanol. Both samples gave perfect protection to steel panels in the humidity tests for over 168 hours. The oil by itself permitted rusting to begin after two hours.

In another type of test, there was established the protective value of the compositions here claimed. A 6% solution of the above sulfonate in the above aviation oil was coated on panels which were immersed in synthetic sea water. At the end of two hours, it was found that rusting had begun on these panels. The addition of 0.5% or 1% of diisobutylphenoxyethoxyethoxyethanol in the 6% sulfonate solution provided complete protection of panels coated with such solutions for forty-eight hours, at which time the tests were discontinued. In the same test were panels coated with a composition comprising 2% of the sulfonate and 1% of the same ether alcohol. These were also free of rust at the end of fortyeight hours of immersion in synthetic sea water. The same result may be obtained by the use of n-decylor n-dodecylor tert.-dodecy1-phenoxyethoxyethoxyethanol in the solutions of petroleum sulfonates in the above oil.

Compositions such as shown above have been used in commercial applications with results which surpassed those indicated by laboratory tests. The practical applications include not only the use of the compositions as lubricating oils in motors but also the use of the compositions to protect metals from both moisture vapor and condensed moisture during use or during storage.

Oils containing petroleum sulfonates and alkylphenoxyethoxyethoxyethanols, when used as mo tor oils, have the virtue of preventing corrosion of aluminum pistons, brass and bronze parts and fittings, and bearing alloys, as well as iron and steel parts, guarding against attack by moisture which condenses out within motors. Furthermore, the compositions used for the protection of gasoline and compression-ignition engines in temporary or long-term storage with an added advantage that the engine may be run to distribute the compositions through the motor.

We claim:

1. A composition of matter consisting essentially of 0.5% to 7.5% of an oil-soluble petroluem sulfonate and 0.05% to 3% of an alkylphenoxyethoxyethoxyethanol having an alkyl group of four to twelve carbon atoms dissolved in a mineral oil having a viscosity of one hundred to fifteen hundred seconds Saybolt at F.

2. A composition of matter consisting essentially of 0.5% to 7.5% of anoil-soluble petroleum sulfonate having a molecular weight between four hundred and one thousand and 0.05% to 3% of ,an oil-soluble alkylphenoxyethoxyethoxyethanol, having an alkyl group of four to twelve carbon atoms dissolved in a mineral oil having a viscosity of one hundred to fifteen hundred se onds Saybolt at 100 F., the percentage of id alkylphenoxyethoxyethoxyethanol used no exceeding that of the petroleum sulfonate.

3. A composition of matter consisting essentially of 0.5% to 7.5% of an oil-soluble petroleum sulfonate of about five hundred to about seven hundred molecular weight and 0.05% to 3% of diisobutylphnoxyethoxyethoxyethanol, the percentage thereot not exceeding that of said sulfonate, dissolved in a mineral oil having a viscosity of one hundred to fifteen hundred seconds Saybolt at 100 F.

FRANK J. GLAVIS. HARRY T. NEED REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 2,075,018 Bruson Mar. 80, 1937 2,176,834 Bruson Oct. 17, 1939 2,408,971 Duncan Oct. 8, 1946 of the invention may be 

